1. Field of the Invention
The present invention relates to an autofocusing apparatus for a camera having a multiple ranging device and, more particularly, to an autofocusing apparatus for a camera having a multiple ranging device capable of ranging a plurality of points within a photographic frame.
2. Description of the Related Art
All conventional cameras have been designed to perform a ranging operation for focusing at only one point on a central portion of a photographic frame. With such a camera, a so-called "object omission" occurs when no object is present at the central portion of a photographic frame. In this case, only an out-of-focus photograph can be obtained.
Under the circumstances, devices capable of ranging a plurality of points within a frame have been invented, and various methods of performing focusing on a specific point of a plurality of points have been proposed. For example, a method of selecting the nearest point in a photographic frame as a focal point is disclosed in U.S. Pat. No. 4,470,681 and the like, and a method of center-priority focusing is disclosed in U.S. Pat. No. 4,748,469 and the like.
The nearest object in a photographic frame is not always a main object. That is, with a simple application of the method of selecting the nearest point, when, for example, an object located behind a table is to be photographed, the lens is focused on the table. As a result, the object becomes out of focus.
On the other hand, with the center-priority focusing method, the "object omission" preventing effect will deteriorate.